A TFT-LCD display generally comprises an array substrate, a color filter, and a liquid crystal layer sandwiched in between. The array substrate comprises an active area having pixels arranged in array, and a source driver and a gate driver outside the active area. The source driver and the gate driver are respectively coupled to the respective pixels for driving the pixels to display.
The TFT-LCD display also requires providing a gamma reference voltage to the source driver. At present in the industry, two ways of generating the gamma voltage to the driver circuit in the liquid crystal panel are utilized: one is to utilize the resistance divider, the other is to add a programmable control chip, as the Power IC shown in FIG. 1. As regarding the latter, the source driver is respectively coupled to the pulse generating circuit and the programmable control chip outside the array substrate. The programmable control chip mainly is employed to provide gamma reference voltage for the source driver.
With the first way, i.e. utilizing the resistance divider, the cost is lower but the way of providing the voltage is not flexible and the adjustment is not convenient. With the second way, i.e. the programmable control chip directly supplies the gamma voltage, such way of providing the voltage is flexible but the cost of the programmable control chip is high. Undoubtedly, the programmable control chip will increase the manufacture cost.